Wasp, biting flies, flies, fleas, fire ants, fruit flies, drain flies, gray leaf spot, grass eating worms (finally saw some moths yesterday laying eggs – worms to follow), chinch bugs and mosquitoes, ahh, summertime in the Lowcountry is here once again!
The rains and high tides have the mosquitoes are out in full force. The Buck Full Moon really has people complaining about the super high population of mosquitoes. Mosquitoes are the number one killer in the world of people and a huge vector for disease.
A few things that you can do yourself in the battle against mosquitoes is scout around the yard for anything that holds water. Old tires, saucers under potted plants, bird baths, old flower containers or pots stacked in a corner, dog toys, kids’ toys, a container by the grill you use to soak wood chips in, a cooler, an old fountain, an upside down 5-gallon bucket that has a lip that holds water, a trash can lid
with a dent, brick work that needs repointing, a hole in a tree and a dog’s water bowl all make great places for mosquitoes to breed. Empty the water out these areas (refill the dog bowl and the bird bath daily). A tarp covering a boat or wood pile can have many pockets that hold water. Sagging gutters hold water. A few empty bottles or cans can end up being thousands of mosquitoes! A bottle cap can be a breeding area. Many mosquitoes can breed in just an ounce of water. I was at a seminar and the speaker was encouraging people to limb up Magnolias (every horticulturalist gasped) so you could easily rake up the leaves because the big leaves held water and therefore were a breeding spot for mosquitoes.
Between pop up thunderstorms, people going on vacation, and people just not mowing enough, gray leaf spot has exploded on St. Augustine grass. I am seeing gray leaf spot on Zoysia as well.
Gray leaf spot (Pyricularia grisea) goes with St. Augustine like grits go with shrimp! Or like chinch bugs go with St. Augustine! To battle gray leaf spot, you are best employing many cultural practices and using limited control products if necessary.
Gray leaf spot looks like someone burned or dripped acid on the leaves of the plant. There are little oblong spots on the leaf. Eventually, these spots grow together and the leaf blade dies. Whole areas of your grass can disappear at once when these leaf blades die.
Culturally there are several things to do to minimize your problem with gray leaf spot. This disease likes high humidity and excessive nitrogen fertilizer. To help alleviate the high humidity, mow your grass to a level that seems abnormal to St. Augustine. Try to get it down to 2 ½ - 3 inches depending on the variety of St. Augustine grass. Also try to mow every 3 – 5 days with a bagger. I don’t usually recommend a bag, and if you don’t have one, just keep it mowed. This mowing will help get sunlight down to the crown of the plant, drying the leaf blades as quickly as possible.
With mowing it is always hard to get someone to modify the frequency of cuts. “The landscaper only comes every 7 or 14 days” or “I mow every Saturday morning”, is what I usually hear. If you don’t want to cut it yourself (saving a trip to the gym and I have been told a cold beer or IPA is extra good after mowing) in between visits by the landscaper, maybe you could hire a neighborhood kid or your kid to just mow the grass. No edging, blowing or string trimming, just a quick mow.
Another alternative to you mowing is applying a growth regulator to your turf. These products work great at slowing your turf’s growth rate. Growth regulators are used extensively on golf courses and athletic fields. Growth regulators do a great job of managing your turf’s growth rate on your home lawn as well.
Consider trimming trees or shrubs to increase air movement through your yard.
This fungus like most fungi likes hot humid weather. Minimize the amount you water as much as possible. Wait until your lawn is getting a blue/green color and your foot prints stay in the lawn after you walk across it before you water. Unfortunately, you can not control rainfall as easily. In the Lowcountry, afternoon thunderstorms are a way of life, so keep the grass mowed as low as you can so it will dry out quickly.
Hold off of the nitrogen fertilizer until you can get this disease under control. If you need some color, you could add a product like Possum’s Minors to give you some green without all the nitrogen. Watch starving your grass because a malnourished yard is more susceptible to disease. Very low rates of an organic fertilizer or cotton burr compost might help it recover.
At Possum’s, I know we have had several customers that swear they control this disease by using our wetting agent with biostimulants, cotton burr compost, and / or SeaHume along with the above cultural practices. You will need to water less with the use of these products, and wetting agents help keep the leaves on the grass plant dry. These products are not fungicides, but customers have seen a correlation of using them and having less disease issues.
If you have to resort to a control product, make sure the product is labeled for Pyricularia grisea. There are many leaf spot diseases on labels of control products but only certain products work on gray leaf spot on St. Augustine and Zoysia. We had one customer come in that had been applying a product that controlled Drechslera spp. and Biopolaris spp. leaf spot; however, the product was not labeled for Pyricularia grisea (watch where you shop).
Strobe Pro G, Heritage and Fame are granular systemic products that are absorbed through the roots and will do a good job on gray leaf spot. Preventive applications for chinch bugs and grass eating worms will save you a panic situation in the future.
Always read and follow product label.
